1 /******************************************************************************
2  * vm_event.h
3  *
4  * Memory event common structures.
5  *
6  * Copyright (c) 2009 by Citrix Systems, Inc. (Patrick Colp)
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to
10  * deal in the Software without restriction, including without limitation the
11  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
12  * sell copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24  * DEALINGS IN THE SOFTWARE.
25  */
26 
27 #ifndef _XEN_PUBLIC_VM_EVENT_H
28 #define _XEN_PUBLIC_VM_EVENT_H
29 
30 #include "xen.h"
31 
32 #define VM_EVENT_INTERFACE_VERSION 0x00000002
33 
34 #if defined(__XEN__) || defined(__XEN_TOOLS__)
35 
36 #include "io/ring.h"
37 
38 /*
39  * Memory event flags
40  */
41 
42 /*
43  * VCPU_PAUSED in a request signals that the vCPU triggering the event has been
44  *  paused
45  * VCPU_PAUSED in a response signals to unpause the vCPU
46  */
47 #define VM_EVENT_FLAG_VCPU_PAUSED        (1 << 0)
48 /* Flags to aid debugging vm_event */
49 #define VM_EVENT_FLAG_FOREIGN            (1 << 1)
50 /*
51  * The following flags can be set in response to a mem_access event.
52  *
53  * Emulate the fault-causing instruction (if set in the event response flags).
54  * This will allow the guest to continue execution without lifting the page
55  * access restrictions.
56  */
57 #define VM_EVENT_FLAG_EMULATE            (1 << 2)
58 /*
59  * Same as VM_EVENT_FLAG_EMULATE, but with write operations or operations
60  * potentially having side effects (like memory mapped or port I/O) disabled.
61  */
62 #define VM_EVENT_FLAG_EMULATE_NOWRITE    (1 << 3)
63 /*
64  * Toggle singlestepping on vm_event response.
65  * Requires the vCPU to be paused already (synchronous events only).
66  */
67 #define VM_EVENT_FLAG_TOGGLE_SINGLESTEP  (1 << 4)
68 /*
69  * Data is being sent back to the hypervisor in the event response, to be
70  * returned by the read function when emulating an instruction.
71  * This flag is only useful when combined with VM_EVENT_FLAG_EMULATE
72  * and takes precedence if combined with VM_EVENT_FLAG_EMULATE_NOWRITE
73  * (i.e. if both VM_EVENT_FLAG_EMULATE_NOWRITE and
74  * VM_EVENT_FLAG_SET_EMUL_READ_DATA are set, only the latter will be honored).
75  */
76 #define VM_EVENT_FLAG_SET_EMUL_READ_DATA (1 << 5)
77 /*
78  * Deny completion of the operation that triggered the event.
79  * Currently only useful for MSR and control-register write events.
80  * Requires the vCPU to be paused already (synchronous events only).
81  */
82 #define VM_EVENT_FLAG_DENY               (1 << 6)
83 /*
84  * This flag can be set in a request or a response
85  *
86  * On a request, indicates that the event occurred in the alternate p2m
87  * specified by the altp2m_idx request field.
88  *
89  * On a response, indicates that the VCPU should resume in the alternate p2m
90  * specified by the altp2m_idx response field if possible.
91  */
92 #define VM_EVENT_FLAG_ALTERNATE_P2M      (1 << 7)
93 /*
94  * Set the vCPU registers to the values in the  vm_event response.
95  * At the moment x86-only, applies to EAX-EDX, ESP, EBP, ESI, EDI, R8-R15,
96  * EFLAGS, and EIP.
97  * Requires the vCPU to be paused already (synchronous events only).
98  */
99 #define VM_EVENT_FLAG_SET_REGISTERS      (1 << 8)
100 /*
101  * Instruction cache is being sent back to the hypervisor in the event response
102  * to be used by the emulator. This flag is only useful when combined with
103  * VM_EVENT_FLAG_EMULATE and does not take presedence if combined with
104  * VM_EVENT_FLAG_EMULATE_NOWRITE or VM_EVENT_FLAG_SET_EMUL_READ_DATA, (i.e.
105  * if any of those flags are set, only those will be honored).
106  */
107 #define VM_EVENT_FLAG_SET_EMUL_INSN_DATA (1 << 9)
108 /*
109  * Have a one-shot VM_EVENT_REASON_INTERRUPT event sent for the first
110  * interrupt pending after resuming the VCPU.
111  */
112 #define VM_EVENT_FLAG_GET_NEXT_INTERRUPT (1 << 10)
113 
114 /*
115  * Reasons for the vm event request
116  */
117 
118 /* Default case */
119 #define VM_EVENT_REASON_UNKNOWN                 0
120 /* Memory access violation */
121 #define VM_EVENT_REASON_MEM_ACCESS              1
122 /* Memory sharing event */
123 #define VM_EVENT_REASON_MEM_SHARING             2
124 /* Memory paging event */
125 #define VM_EVENT_REASON_MEM_PAGING              3
126 /* A control register was updated */
127 #define VM_EVENT_REASON_WRITE_CTRLREG           4
128 /* An MSR was updated. */
129 #define VM_EVENT_REASON_MOV_TO_MSR              5
130 /* Debug operation executed (e.g. int3) */
131 #define VM_EVENT_REASON_SOFTWARE_BREAKPOINT     6
132 /* Single-step (e.g. MTF) */
133 #define VM_EVENT_REASON_SINGLESTEP              7
134 /* An event has been requested via HVMOP_guest_request_vm_event. */
135 #define VM_EVENT_REASON_GUEST_REQUEST           8
136 /* A debug exception was caught */
137 #define VM_EVENT_REASON_DEBUG_EXCEPTION         9
138 /* CPUID executed */
139 #define VM_EVENT_REASON_CPUID                   10
140 /*
141  * Privileged call executed (e.g. SMC).
142  * Note: event may be generated even if SMC condition check fails on some CPUs.
143  *       As this behavior is CPU-specific, users are advised to not rely on it.
144  *       These kinds of events will be filtered out in future versions.
145  */
146 #define VM_EVENT_REASON_PRIVILEGED_CALL         11
147 /* An interrupt has been delivered. */
148 #define VM_EVENT_REASON_INTERRUPT               12
149 /* A descriptor table register was accessed. */
150 #define VM_EVENT_REASON_DESCRIPTOR_ACCESS       13
151 /* Current instruction is not implemented by the emulator */
152 #define VM_EVENT_REASON_EMUL_UNIMPLEMENTED      14
153 
154 /* Supported values for the vm_event_write_ctrlreg index. */
155 #define VM_EVENT_X86_CR0    0
156 #define VM_EVENT_X86_CR3    1
157 #define VM_EVENT_X86_CR4    2
158 #define VM_EVENT_X86_XCR0   3
159 
160 /*
161  * Using custom vCPU structs (i.e. not hvm_hw_cpu) for both x86 and ARM
162  * so as to not fill the vm_event ring buffer too quickly.
163  */
164 struct vm_event_regs_x86 {
165     uint64_t rax;
166     uint64_t rcx;
167     uint64_t rdx;
168     uint64_t rbx;
169     uint64_t rsp;
170     uint64_t rbp;
171     uint64_t rsi;
172     uint64_t rdi;
173     uint64_t r8;
174     uint64_t r9;
175     uint64_t r10;
176     uint64_t r11;
177     uint64_t r12;
178     uint64_t r13;
179     uint64_t r14;
180     uint64_t r15;
181     uint64_t rflags;
182     uint64_t dr7;
183     uint64_t rip;
184     uint64_t cr0;
185     uint64_t cr2;
186     uint64_t cr3;
187     uint64_t cr4;
188     uint64_t sysenter_cs;
189     uint64_t sysenter_esp;
190     uint64_t sysenter_eip;
191     uint64_t msr_efer;
192     uint64_t msr_star;
193     uint64_t msr_lstar;
194     uint64_t fs_base;
195     uint64_t gs_base;
196     uint32_t cs_arbytes;
197     uint32_t _pad;
198 };
199 
200 /*
201  * Only the register 'pc' can be set on a vm_event response using the
202  * VM_EVENT_FLAG_SET_REGISTERS flag.
203  */
204 struct vm_event_regs_arm {
205     uint64_t ttbr0;
206     uint64_t ttbr1;
207     uint64_t ttbcr;
208     uint64_t pc;
209     uint32_t cpsr;
210     uint32_t _pad;
211 };
212 
213 /*
214  * mem_access flag definitions
215  *
216  * These flags are set only as part of a mem_event request.
217  *
218  * R/W/X: Defines the type of violation that has triggered the event
219  *        Multiple types can be set in a single violation!
220  * GLA_VALID: If the gla field holds a guest VA associated with the event
221  * FAULT_WITH_GLA: If the violation was triggered by accessing gla
222  * FAULT_IN_GPT: If the violation was triggered during translating gla
223  */
224 #define MEM_ACCESS_R                (1 << 0)
225 #define MEM_ACCESS_W                (1 << 1)
226 #define MEM_ACCESS_X                (1 << 2)
227 #define MEM_ACCESS_RWX              (MEM_ACCESS_R | MEM_ACCESS_W | MEM_ACCESS_X)
228 #define MEM_ACCESS_RW               (MEM_ACCESS_R | MEM_ACCESS_W)
229 #define MEM_ACCESS_RX               (MEM_ACCESS_R | MEM_ACCESS_X)
230 #define MEM_ACCESS_WX               (MEM_ACCESS_W | MEM_ACCESS_X)
231 #define MEM_ACCESS_GLA_VALID        (1 << 3)
232 #define MEM_ACCESS_FAULT_WITH_GLA   (1 << 4)
233 #define MEM_ACCESS_FAULT_IN_GPT     (1 << 5)
234 
235 struct vm_event_mem_access {
236     uint64_t gfn;
237     uint64_t offset;
238     uint64_t gla;   /* if flags has MEM_ACCESS_GLA_VALID set */
239     uint32_t flags; /* MEM_ACCESS_* */
240     uint32_t _pad;
241 };
242 
243 struct vm_event_write_ctrlreg {
244     uint32_t index;
245     uint32_t _pad;
246     uint64_t new_value;
247     uint64_t old_value;
248 };
249 
250 struct vm_event_singlestep {
251     uint64_t gfn;
252 };
253 
254 struct vm_event_debug {
255     uint64_t gfn;
256     uint32_t insn_length;
257     uint8_t type;        /* HVMOP_TRAP_* */
258     uint8_t _pad[3];
259 };
260 
261 struct vm_event_mov_to_msr {
262     uint64_t msr;
263     uint64_t value;
264 };
265 
266 #define VM_EVENT_DESC_IDTR           1
267 #define VM_EVENT_DESC_GDTR           2
268 #define VM_EVENT_DESC_LDTR           3
269 #define VM_EVENT_DESC_TR             4
270 
271 struct vm_event_desc_access {
272     union {
273         struct {
274             uint32_t instr_info;         /* VMX: VMCS Instruction-Information */
275             uint32_t _pad1;
276             uint64_t exit_qualification; /* VMX: VMCS Exit Qualification */
277         } vmx;
278         struct {
279             uint64_t exitinfo;           /* SVM: VMCB EXITINFO */
280             uint64_t _pad2;
281         } svm;
282     } arch;
283     uint8_t descriptor;                  /* VM_EVENT_DESC_* */
284     uint8_t is_write;
285     uint8_t _pad[6];
286 };
287 
288 struct vm_event_cpuid {
289     uint32_t insn_length;
290     uint32_t leaf;
291     uint32_t subleaf;
292     uint32_t _pad;
293 };
294 
295 struct vm_event_interrupt_x86 {
296     uint32_t vector;
297     uint32_t type;
298     uint32_t error_code;
299     uint32_t _pad;
300     uint64_t cr2;
301 };
302 
303 #define MEM_PAGING_DROP_PAGE       (1 << 0)
304 #define MEM_PAGING_EVICT_FAIL      (1 << 1)
305 
306 struct vm_event_paging {
307     uint64_t gfn;
308     uint32_t p2mt;
309     uint32_t flags;
310 };
311 
312 struct vm_event_sharing {
313     uint64_t gfn;
314     uint32_t p2mt;
315     uint32_t _pad;
316 };
317 
318 struct vm_event_emul_read_data {
319     uint32_t size;
320     /* The struct is used in a union with vm_event_regs_x86. */
321     uint8_t  data[sizeof(struct vm_event_regs_x86) - sizeof(uint32_t)];
322 };
323 
324 struct vm_event_emul_insn_data {
325     uint8_t data[16]; /* Has to be completely filled */
326 };
327 
328 typedef struct vm_event_st {
329     uint32_t version;   /* VM_EVENT_INTERFACE_VERSION */
330     uint32_t flags;     /* VM_EVENT_FLAG_* */
331     uint32_t reason;    /* VM_EVENT_REASON_* */
332     uint32_t vcpu_id;
333     uint16_t altp2m_idx; /* may be used during request and response */
334     uint16_t _pad[3];
335 
336     union {
337         struct vm_event_paging                mem_paging;
338         struct vm_event_sharing               mem_sharing;
339         struct vm_event_mem_access            mem_access;
340         struct vm_event_write_ctrlreg         write_ctrlreg;
341         struct vm_event_mov_to_msr            mov_to_msr;
342         struct vm_event_desc_access           desc_access;
343         struct vm_event_singlestep            singlestep;
344         struct vm_event_debug                 software_breakpoint;
345         struct vm_event_debug                 debug_exception;
346         struct vm_event_cpuid                 cpuid;
347         union {
348             struct vm_event_interrupt_x86     x86;
349         } interrupt;
350     } u;
351 
352     union {
353         union {
354             struct vm_event_regs_x86 x86;
355             struct vm_event_regs_arm arm;
356         } regs;
357 
358         union {
359             struct vm_event_emul_read_data read;
360             struct vm_event_emul_insn_data insn;
361         } emul;
362     } data;
363 } vm_event_request_t, vm_event_response_t;
364 
365 DEFINE_RING_TYPES(vm_event, vm_event_request_t, vm_event_response_t);
366 
367 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
368 #endif /* _XEN_PUBLIC_VM_EVENT_H */
369 
370 /*
371  * Local variables:
372  * mode: C
373  * c-file-style: "BSD"
374  * c-basic-offset: 4
375  * tab-width: 4
376  * indent-tabs-mode: nil
377  * End:
378  */
379